Nissan Leaf Battery

[TonyWilliams]

The battery is neither air cooled (with or without a fan), nor liquid cooled. The closest thing to cooling is conductive losses through the car's steel body.

Isn't the underside of the pack exposed? That would make the pack as a whole passively air-cooled by the airflow under the vehicle.

Based on what I've read on this forum, the pack does not need active cooling even in a Phoenix summer. What it needs is heating in the colder climates. That's essentially the opposite problem and one that's addressed by adding heating pads inside the pack.
=Smidge=

Yes, way easier to heat the pack, than try and cool it. The bottom of the pack is not exposed, and is actually covered by aerodynamic covers over the entire bottom of the car. That's not to say some air won't get in there; of course, it will.

 

[EdmondLeaf]

I think that is the LEAF battery characteristics
http://www.greencarcongress.com/2008/05/aesc-lithium-io.html

 

[surfingslovak]

I think that is the LEAF battery characteristics
http://www.greencarcongress.com/2008/05/aesc-lithium-io.html

Interesting article, thank you for mentioning it. However, Mike seems to discuss an earlier version of AESC batteries there. I vaguely recall reading about the L3-10 cells before, and when you look at the nominal voltage (3.6V) and the rated capacity (13Ah), it's different from what's in the Leaf. I believe that the most detailed and authoritative source of information for the production batteries used in MY2011 and MY2012 Leaf is the manufacturer website. This has been discussed several times over the past year on the forum. If you found something new, that would be awesome. I believe that there would be quite a bit of interest in a bench test conducted by an independent 3rd party.

http://www.eco-aesc-lb.com/en/product.html

 

[EdmondLeaf]

Of course I was wrong that on previous link. Sorry

 

[GotMyleaf]

I don't have anything to add, but I have really been wondering about the thermal management of the LEAF and have dismissed it as MAGIC. I have used DC fast charging multiple times and have only seen the temp increase, by one bar, one time. The temp will increase during a drive sometimes but only to six bars. During the summer it hit seven bars, but never higher. I have only felt heat from the inverter during level 2 charging which has a liquid cooling system. However, the battery seems unaffected during charging. I kept reading that DC fast charging is discouraged due to heat which is NOT my experience. I have DC fast charged twice in one day too.

I can't confirm this, but a Mitsubishi employee told me that the i-Miev uses it's A/C to cool the battery. If that's true it makes sense to me, but I know that the LEAF battery does not use any power for battery thermal management.

All I have are questions.

 

[EVDRIVER]

I don't have anything to add, but I have really been wondering about the thermal management of the LEAF and have dismissed it as MAGIC. I have used DC fast charging multiple times and have only seen the temp increase, by one bar, one time. The temp will increase during a drive sometimes but only to six bars. During the summer it hit seven bars, but never higher. I have only felt heat from the inverter during level 2 charging which has a liquid cooling system. However, the battery seems unaffected during charging. I kept reading that DC fast charging is discouraged due to heat which is NOT my experience. I have DC fast charged twice in one day too.

I can't confirm this, but a Mitsubishi employee told me that the i-Miev uses it's A/C to cool the battery. If that's true it makes sense to me, but I know that the LEAF battery does not use any power for battery thermal management.

All I have are questions.

The "inverter" has noting to do with DC fast charging as it goes straight to the pack. The inverter is part of the drive system not the charging system. If one were doing 70 on the freeway in warmer temps and repeated fast charge there would due a marked increase in temp but not for normal single charge use unless it is very hot outside and the car is driven harder.

 

[JPWhite]

During the summer it hit seven bars, but never higher.

Same here. 7 bars is the highest I have sen it go in 107 degree temps after a hard drive and a charge. I'm keeping a log of temps and battery bars, to get an idea of what each bar represents. I'll post it once I've been through 4 seasons with the car.

JP

 

[FairwoodRed]

Same here. 7 bars is the highest I have sen it go in 107 degree temps after a hard drive and a charge. I'm keeping a log of temps and battery bars, to get an idea of what each bar represents. I'll post it once I've been through 4 seasons with the car.

JP

Sounds like what you are logging for can be found in the post by Surfingslovak: http://www.mynissanleaf.com/viewtopic.php?f=30&t=5850&start=10" onclick="window.open(this.href);return false;

The biggest thing that I got from this chart is that the bars are non linear - not much change in the normal range and lots of change at the top/bottom.

 

[planet4ever]

That's odd. My car lives outside, and I have been seeing 4 bars (and one unavailable regen bubble) when I first get in the car. What makes that odd is that I usually don't even drive the car in the morning, and the minimum temperatures have been in the high 30's. We haven't had any frost here at all. Or am I reading that wrong? Does segment 5 go off at 50.5 degrees, not 26.6 degrees?

By the way, my battery usually warms up to 5 bars after I drive it a bit, and the extra regen bubble becomes available.

Ray

 

[JPWhite]

That's odd. My car lives outside, and I have been seeing 4 bars (and one unavailable regen bubble) when I first get in the car. What makes that odd is that I usually don't even drive the car in the morning, and the minimum temperatures have been in the high 30's. We haven't had any frost here at all. Or am I reading that wrong? Does segment 5 go off at 50.5 degrees, not 26.6 degrees?

By the way, my battery usually warms up to 5 bars after I drive it a bit, and the extra regen bubble becomes available.

Ray

Yeah. I have documented 4 bars at 36 degrees as well. Soemthing awry with the chart.

 

[DaveEV]

That's odd. My car lives outside, and I have been seeing 4 bars (and one unavailable regen bubble) when I first get in the car. What makes that odd is that I usually don't even drive the car in the morning, and the minimum temperatures have been in the high 30's. We haven't had any frost here at all. Or am I reading that wrong? Does segment 5 go off at 50.5 degrees, not 26.6 degrees?

By the way, my battery usually warms up to 5 bars after I drive it a bit, and the extra regen bubble becomes available.

Yeah. I have documented 4 bars at 36 degrees as well. Soemthing awry with the chart.

5 bars showing means battery between 50.5F-74.3F.
4 bars showing means battery between 26.6F-50.5F.